اسم ( noun )
• (1) تعریف: a highly reactive chemical element of the alkali metal group that has fifty-five protons in each nucleus and that occurs in pure form as a soft, silvery metal melting to a heavy liquid just above room temperature. (symbol: Cs)
• (2) تعریف: a salt compound of cesium and chlorine used in medicine and research as a high-density purification agent; cesium chloride.